A total of 201, 218, 258, 253, and 244 polymorphic AFLP and RAPD markers were 9501, 9502, 55 - 3 x 8380 - 1, 8380 - 1 x 55 - 3, and 55 - 1 x 8380 - 1, respectively .   each each in ea ic RAPD loci were scored for each RAPD 8380 - 1 x 55 - integ 3 x 8 d 55 - 1 x 8380 - 1 populations, focused on markers exhibiting conta 1) . M welve different map locations, chac ed clustering of Eco RI + Mse I AFLP map nnellii and suggested that regio ndom distribution of markers on the from were mark potat popu arity over the 3' end to a region n Arabidopsis thaliana chromosome 1 (BAC F3F20 . 1; annotated as callose synthase) .    This region may be a key site for determination of solanidine in Solanum spp . , solanidine or solasodine in S . tuberosum x S . berthaultii progeny (Yencho et al . 1998), and for accumulation of solanidine or leptinidine in S . chacoense (Ronning et al . 1999) . Marker UBC370 - 1500 exhibited linkage to a number of AFLP and RAPD markers in linkage group 1 marker frameworks for 55 - 3x8380 - 1/8380 - 1x55 - 3 and 9501/9502 populations .   This marker was also detected in the high - leptine genotype 8380 - 1 . As a result, we would expect no correlation between presence of the marker and leptine content in the 55 - 3x8380 - 1/8380 - 1x55 - 3 and 55 - 1x8380 - 1 families . These results, together with previous genetic studies involving crosses with 8380 - 1 (Ronning et al . , 1998), suggest that additional genetic factors likely influence the inheritance and expression of leptine glycoalkaloids in S . chacoense .   The markers mapped here provide an opportunity for additional fine mapping of this region on chromosome 1 and investigation of glycoalkaloid inheritance . scored in families These markers were primarily AFLP loci, but also included an average of 38 RAPD loci in of the five families .   An average of 17 polymorphic loci (range 9 - 33) were scored for AFLP primer pair . An average of 39 AFLP loci were monomorphic across all individuals ch family .   One to nine (mean 3 . 6) polymorph primer in these families .   Unambiguous mapped markers in families 9501, 9502, 3, 55 - 3 x 8380 - 1, and 55 - 1 x 8380 - 1 totaled 158, 141, 180, 185, and 118, respectively .   The rated map for chromosome 1, derived from merging linkage groups from 9501/9502, 55 - 380 - 1/8380 - 1 x 55 - 3, an linkage with chromosome 1 marker UBC370 - 1500 and allied linkage groups . This map